Relationship Between Type 2 Diabetes and White Matter Hyperintensity: A Systematic Review

Area of Science:

• Neurology
• Endocrinology
• Radiology

Background:

• White matter (WM) disease is a significant factor in cognitive decline and dementia.
• White matter lesions (WMLs), visualized as white matter hyperintensities (WMH) on MRI, are increasingly studied in relation to systemic diseases.
• Type 2 diabetes mellitus (T2DM) has been previously associated with WMH, necessitating a focused review of current evidence.

Purpose of the Study:

• To systematically review the literature on the association between T2DM and WMH.
• To explore the relationship between T2DM presence, its progression, complications, and WMH.
• To investigate the links between T2DM-related brain structural changes, cognitive function, and WMH.

Main Methods:

• Literature search conducted in PubMed and Cochrane databases.
• Focus on studies published within the last five years.
• Review and synthesis of findings on T2DM, WMH, and cognitive outcomes.

Main Results:

• Most studies indicate larger WMH volume and reduced WM integrity in T2DM patients.
• Cognitive deficits in memory, attention, and executive functions in T2DM correlate with observed brain structural changes.
• Diabetic microangiopathy and peripheral neuropathy are potential contributors to WMH, implicating the brain as a target organ.
• Insulin resistance, fasting insulin, high HbA1c, and high glucose variability are associated with WMH, whereas overall glycemic control is not consistently linked.

Conclusions:

• T2DM is significantly associated with increased WMH and impaired white matter integrity.
• WMH in T2DM patients contribute to cognitive decline, particularly in executive functions and memory.
• Diabetic complications like microangiopathy may directly affect brain white matter, underscoring the systemic impact of T2DM.